1. Field of the Invention:
This invention relates to an apparatus for applying a length of tape to a reusable envelope closure. More particularly, the envelope has a closure flap provided with a piece of tape dispensed by the apparatus of the present invention capable of adhering a plurality of times to the main body of the envelope without losing its effectiveness.
2. Description of the Prior Art:
Canadian Pat. No. 745,888, issued Nov. 8, 1966, discloses a reusable envelope in which a flap of the envelope is adhered to the main body. An aperture is punched in the flap and covered by an adhesive material, such as the well known adhesive tape marketed under the trademark SCOTCH TAPE. A second tape is fixed on the main body of the envelope which has a glossy surface. The position of this tape is beneath the closure flap of the envelope when the closure flap is in its closed position. When the tacky surface of the adhesive tape comes in contact with the glossy surface of the tape on the main body, a good reliable bond is formed to seal the envelope. However, the tacky surface of the adhesive tape and closure flap may be pulled away from the glossy surface of the tape on the main body to break the bond and the glossy surface retains very little or no tacky material from the adhesive tape. Therefore, the closure may be resealed a number of times.
U.S. Pat. No. 3,906,844, issued Sept. 23, 1975, discloses an apparatus for producing the envelope closure illustrated in Canadian Pat. No. 745,888. The envelopes having already been formed without the reusable closure, are fed in spaced relation along a conveyor. The apparatus includes means operative to open the closure flap of each envelope as the envelope is being moved along the conveyor, means to cut an opening in the flap, a first tape dispensing means for fixing on the main body of the envelope a band of material having a glossy surface, the band of material being disposed in a position corresponding to the closure flap opening when it is sealed to the main body, and a second tape dispensing means for applying and fixing an adhesive tape on the flap over the opening to form the reusable closure seal for the envelope.
The same tape dispensing apparatus in U.S. Pat. No. 3,906,844 is used to apply both the adhesive tape and glossy band to the envelope. The apparatus includes a tape supply roll from which the tape is fed to a rotatable applicator wheel, while suitable tension is maintained on the tape. A rotatable knife whose axis is in the same horizontal plane as the axis of the applicator wheel is provided so as to rotate in a direction opposite to the applicator wheel. The knife has an edge which is capable of engaging the applicator wheel to transversely cut the continuous band of tape. After a desired length of tape is cut, a suction device retains the length of tape against the outer periphery of the applicator wheel until the tape meets the main body of the envelope or the closure flap having the opening, as the case may be, to apply the tape to the envelope. The tape must be capable of sliding relative to the circumference of the applicator wheel in order to assure delivery of a length of tape which is suitable to overlap the opening cut in the flap, or alternatively, of a length to traverse the main body of the envelope and no more. A feed control to accomplish this is not disclosed.